Process for the manufacture of stable preparations having a high content of commercial lecithin



PROCESS FOR THE MANUFACTURE OF STABLE PREPARATIONS HAVING A HIGH CONTENTOF COIWMERCIAL LECITHIN Carl Heinz Buer, Cologne-Marienburg, Germany NDrawing. Application February 26, 1936, Serial No. 65,920. In GermanyMay 2, 1931 6 Claims. (01. 16782) As is well known high percentagecommercial quality of the lecithin used cannot be very relecithin is ofa salve-like highly stickyconsistenliably estimated. cy, which greatlyhinders the use of lecithin It has now been found that high percentagein original substance for therapeutic purposes. commercial lecithin inoriginal substance can be In the trade, pure lecithin in originalsubstance worked up, with the aid of mechanicalappliances has hithertobeen packedand stored only in and without the admixture of other andnonclosed airtight containers, such as small porcesticky substances intosmall. uniformly 'dosed lain or glass jars or pots, but, owing to thesticky, non-sticky and stable lecithin bodies. For this wax-likeconsistency of the lecithin, this form of purpose thorough drying of thehigh percentage 10 packing makes it almost impossible to measurecommercial lecithin is the first necessity. As is 10 out accurate singledoses, such as are necessary well known, the lecithin of commerce alwaysconfor'therapeutic purposes. For the therapeutic tains a comparativelylarge amount of moisture. use, however, small portions or bodies oflecithin, In the usual method of obtaining lecithin drying accuratelydivided oif, are necessary. Owing to is generally carried out in anapparatus of comthe highly unctuous and sticky properties of theparatively large capacity. Owing to the strongly l5 lecithin it has nothitherto been possible, with hygroscopic properties of lecithin itcannot be the aid of mechanical appliances, to produce brought toasubstantially anhydrous condition by from high percentage commerciallecithin in the usual method of drying it in a comparatively originalsubstance, small nonsticky lecithin bodies thick layer. Tests oncommercial lecithin dried which can be packed. 0n the contrary, the onlyin this way show an average water content of 20 method practised indosing out the pure subfrom 4% to 6%. It is to this moisture contentstance has been to measure it out by hand into that the highly stickyproperties of the high gelatine capsules. This method of dosage,howpercentage lecithin of commerce are to be ascribed ever, is not veryappropriate, neither does it and this is why the product of the knownmethpossess any advantages. The gelatine capsules, 0d of dehydrationcannot be worked up mechani- 5 of course, have to be swallowed and thiscircally into pills and the like. cumstance, alone, makes it diihcult,or even impos- In the process of the present invention, theresible inmany cases, for patients to take the subfore, the lecithin is dried toan extraordinarily stance. Again, hand filling of the capsules is inhighdegree, in suitable drying apparatus, ei-

accurate and troublesome while at the same time ther under vacuum orotherwise. This very thor- 30 the use of gelatine capsules substantiallyinough drying is rendered possible by applying the creases the cost ofthe marketed product. lecithin to drying plates in very thin layers,say,

For therapeutic purposes, therefore, lecithin about 1 to 2 mm. thick. Bythis expedient the has hitherto been mainly used in admixture with watercontent of the lecithin can be reduced to other substances and, in orderto make mechan- 1% or less. Lecithin dried in this way is almost 35 icalhandling of the lecithin and the production anhydrous and has a solid,almost mealy structherefrom of small accurately measured lecithinture,so that it no longer possesses the plastic, containing bodies possible,it has been mixed kneadable consistency necessary for mechanical withfrom 70% to 95% of mainly pulverulent and treatment. Now it has beenfound that this a1- non-sticky substances. In this way kneadable mostanhydrous lecithin can be restored to a 40 but non-sticky masses areobtained, which can plastic, kneadable consistency very convenientlysubsequently be worked up, by suitable mechaniby the addition of a smallquantity of alcohol, say, cal appliances, into pills, pastilles, dropsor tabfrom 5% to 6%. However, in contradistinction lets. These methodsof dosage, however, have to lecithin which contains water, lecithinwhich the disadvantage that considerable quantities of has been renderedplastic by this small addition 45 ballast materials have to be used towork up a of alcohol nolonger possesses the disadvantagecomparativelysmall quantity of lecithin. Furous sticky properties hereinbeforereferred to. more, the pills, tablets and drops manufactured It can,therefore, be divided up just as it is, by in this way contain only asmall amount of high means of mechanical appliances, into uniformpercentage commercial lecithin. Thus, in order lecithin bodies, withouteven soiling the mechani- 5 to administer several grams of lecithin tothe cal parts. In this Way balls, small sticks or tablets body, acomparatively large number of pills, tabcan be formed from the lecithintreated in the lets or drops have to be taken when the substance mannerdescribed. is dosed in this way. Another disadvantage is Owing, however,to the strongly hygroscopic that, owing to the considerable admixtures,the properties of lecithin the bodies produced from 55 covering layer.

it in this way and put into storage would, in a very short time, take upmoisture again from the air and, consequently,.would stick together.This absorption of water would also strongly prejudice the keepingqualities of the lecithin bodies if stored for any considerable lengthof time. It has been found that these disadvantages can be avoided bycovering the mechanically formed lecithin bodies, preferably immediatelyafter their production, with a thin coating of some knownwater-repelling medium of as high a melting point as possible (e. g.refined beeswax, palmitin, stearin or a similar substance) at atemperature of 40 to 50 C. the lecithin bodies being dipped by suitableappliances into the melted coating substances and then allowed to coolrapidly. It has been found that a completely enveloping coating of thewater repelling medium can be obtained on the lecithin bodies if thelatter be coated immediately after the lecithin has been driedpractically to the anhydrous state and divided up into doses or smallbodies. If these lecithin bodies be allowed to absorb only a few percent of water again, a completely enveloping coating of water repellingmedium can no longer be obtained.

The coating of the lecithin bodies makes them airtight on the surface sothat, even if they are stored for a long time, no trace of moisture fromthe air can penetrate into them. Thus, after the coating treatment theycan be mechanically wrapped in paper and packed in boxes, as they remainperfectly dry on the outside and have sufiicient strength imparted tothem by the thin Furthermore, the slight addition of alcohol inconjunction with the airtight covering of the lecithin bodies definitelyprevents deterioration of the lecithin, even when the bodies are storedfor a very long-time. It is well known that when alcohol is used as apreservative for organic substances an addition of at least 15% ofalcohol is required; with smaller additions of alcohol the preservationof such substances is not adequately ensured. It

has, however, been found that, by combining the action of the airtightcoating on the lecithin bodies with the simultaneous use of alcohol,reliable preservation of the lecithin can be obtained with an additionof only 5% of alcohol. This discovery is of special importance because,for many therapeutic uses of lecithin a relatively high alcohol contentwould be most undesirable.

Another advantage of the new method of dosing and preserving lecithinresides in the use of mechanical dosing and packing means instead ofperforming these operations manually.

'This is particularly important from a hygienic standpoint, in view ofthe therapeutic uses to which the substance is put. Finally, the methodis considerably'cheaper and more simple than measuring out the lecithininto gelatine capsules or working it up with large quantities of addedsubstances for the purpose of producing pills, pastilles, drops ortablets.

What I claim is:-

1. Process of producing stable formed bodies of substantially purecommercial lecithin, 'consisting in drying the lecithin in thin layersto a moisture content of not over 1%, adding a small quantity of alcoholto the lecithin so dried, immediately dividing and forming the lecithininto bodies of predetermined dosage and applying a superficial coatingof a water repelling substance to said bodies.

2. Process of producing stable formed bodies I of substantially purecommercial lecithin, consisting in drying the lecithin in thin layers toa moisture content of not over 1%, adding to the lecithin so dried aquantity of alcohol substantially less than that normally required toensure sustained preservation of organic sub stances, dividing andforming the lecithin with the alcohol addition into small bodies ofpredetermined dosage and applying to such bodies a superficial airtightand water-repellant coating.

3. Process according to claim 1, in which the thickness of the layers oflecithin being dried is from 1 to 2 mm.

4. Process according to claim 1, and in which the quantity of alcoholadded is 5 to 6% of the dried lecithin.

5. Process according to claim 1, and in which the superficial coating ofthe lecithin bodies is effected by dipping the bodies in a melt ofwaterrepelling substance having a melting point of about 40 to C.

6. Process of making stable preparations of substantially pure lecithin,consisting in reducing the moisture content of the lecithin to about 1%,adding to the dried lecithin alcohol in a proportion sufilcient torender it plastic but insufficient for its sustained preservation,dividing and forming the plastic lecithin into bodies of predetermineddosage and completely enveloping each of the said bodies in an airtightcovering of water-repellent material the production and coating of theindividual bodies being effected before the lecithin mixed with alcoholhas time to absorb any appreciable moisture from i the atmosphere.

CARL HEINZ BUER.

